A woman in her 80s developed a feeling of abnormal sensation in her face and excessive salivation. She was diagnosed with right facial nerve paralysis and was admitted to a local hospital. On admission, serum creatinine level was 0.54mg/dL and estimated glomerular filtration rate was 79mL/min/1.73m2. She was started on oral valacyclovir at a dose of 3,000mg/day to treat the right facial nerve paralysis. However, 5 days after starting oral administration, she developed generalized fatigue, vertigo, and vomiting. Serum creatinine level rose to 4.99mg/dL with mild disturbance of consciousness, so she was transported to our hospital on suspicion of acyclovir-induced encephalopathy. We performed hemodialysis for 3 consecutive days to remove the acyclovir from the circulation, which subsequently improved all her symptoms. She was later diagnosed with allergic tubulointerstitial nephritis based on renal biopsy.After discharge from our hospital, laboratory data showed a serum creatinine level of 0.67mg/dL. We later confirmed that the serum acyclovir level before the first hemodialysis session had been very high (11.9μg/mL).

Prolonged cough in coronavirus disease 2019 (COVID-19) is not only uncomfortable for patients, but also prolongs the length of stay in an isolation facility. This results in delays in patients' return to their daily life. Therefore, the prompt treatment of cough is important. In this report, we used Japanese traditional (Kampo) medicine, chikujountanto for the treatment of cases with residual cough, airway secretions, slight fever, anxiety, and insomnia, several days after the onset of coronavirus. From October 2020 to September 2021, we prescribed chikujountanto for thirty-three COVID-19 patients with prolonged cough in an isolation facility. Seven patients (6 women and 1 man with ages ranging 37-70 years) were treated with no other medication. Comorbid symptoms included slight fever, sputum, sore throat, nasal discharge, headache, anxiety/insomnia, and taste/olfactory disorders. The start date of treatment ranged from 9 to 21 days after the onset of COVID-19, and the time until cough and comorbid symptoms improved to values less than NRS 2 or less, was 2 to 6 days after treatment. Three patients had persistent cough and needed to switch to other medication. In COVID-19, chikujountanto may be useful for coughing during the period when the peak of the viral proliferative phase has passed but airway inflammation is still present.